The purpose of this application is to determine the non-hazardous power levels and the mechanism of formation of cataract following chronic occupational exposures to radiation in the near IR (700-2000 nm). The IR radiation will be delivered to the iris and lens both together and separately. After the chronic IR exposures are made, the lenses will be analyzed by sensitive tests to detect any early or precataractous changes. Optical tests will be used to detect the presence of any abnormal molecules resulting from the IR exposure and to correlate with changes in alpha crystallin levels documented by electrophoresis. These will include spectral absorption, fluorescence and reflection measurements.